Abstract

This paper tackles the sum-rate maximization in FBMC systems. It
is well-known that multipath fading destroys the orthogonality of
the subcarriers, which brings a non-convex problem that can be interpreted
as the maximization of a difference of concave functions.
This reformulation enables using DC programming to find the global
optimal but the complexity becomes unaffordable in the FBMC context.
Aiming at reducing the complexity we have devised a new suboptimal
algorithm. The idea consists in smartly partitioning the band
into three subsets so that subcarrier signals belonging to the same
subset do not overlap in the frequency domain. If subsets maximize
sequentially their own rate the original problem is turned into three
simpler problems. Simulation-based results show that the sum-rate
is in the same order as the water-filling used in OFDM and a suboptimal
solution based on DC programming. However, the addressed
technique enables saving up to 25% of the power at SNR=22 dB.